1. Field of the Invention
The present invention relates generally to a carrying case, and more particularly, to a carrying case for securely transporting a delicate electronic instrument such as a notebook computer.
2. Description of the Background Art
"Laptop" and "notebook" computers, that is, personal computers so reduced in size and weight as to be conveniently carried and employed while traveling, have enjoyed widespread acceptance of late. Unfortunately, it is difficult to make notebook computers compact while at the same time making them rugged enough to withstand being dropped or otherwise subjected to shock loading. The small size of today's notebook computers leaves little or no room inside for shock absorbing materials to protect the vulnerable parts of the computer, such as the LCD screen, the hard drive, the plastic outer case, and the various connectors.
The effect of being dropped or hit is measured in G's, which represents an acceleration of 32 feet/sec.sup.2. Each computer manufacturer's design is different, so there is no universally safe level of shock for notebook computer cases and connectors. However, the manufacturers of hard drives typically specify that their drives can withstand shocks in the range of 75 to 200 G. The manufacturers of LCD screens, on the other hand, guarantee their screens to withstand shocks of only about 50 G, a level which can be reached by dropping a notebook computer from a height of only six inches. Since carrying cases for notebook computers are usually hand held or hung from shoulder straps more than six inches from the ground, it is important that they provide adequate protection from the falls and bumps typically encountered in every day use.
Most manufacturers of carrying cases for notebook computers incorporate into their cases foam padding ranging in thickness from about one-half to about three inches. Foam padding will protect the computer until completely compressed, which is typically half of the thickness of the foam pad. Thus, three inches of padding will protect a computer only through a distance of about one and a half inches. Tests have shown that in carrying cases provided with two inches of foam padding, the 50 G threshold for LCD screens is exceeded in drops from as little as eight inches.
A carrying case offering superior protection against shocks is disclosed in U.S. Pat. No. 5,217,119 and is marketed by PORT Computer Cases of South Norwalk, Conn. The case includes a suspension system which uses an elastic sling construction built into the case. The computer is protected within the sling through the full distance of the fall, without resting on a foam barrier. The empty space below the sling, to the bottom of the case, provides twice as much protection as an equivalent amount of foam rubber padding.